Upper Permian Nayixiong Formation volcanic rocks from northern Qiangtang-Qamdo landmass of the Tibetan Plateau have many geochemical characteristics and zircon U-Pb dating data. The main volcanic rocks are basalt, andesite-basalt, andesite, rhyolite, tuff, which have the characteristics of alkaline basalt to acidic rhyolite. The result of the geochronologic study of zircon U-Pb dating data shows that the volcanic eruption ages vary from 251.1±4.8 Ma to 249.6±1.3 Ma. Geochemical characteristics show that the rocks are characterized by high SiO₂(74.85%~77.55%) and Na₂O+K₂O(5.40%~6.61%), low MgO, K₂O and CaO as well as low and stable Al₂O₃ content. The average Rittmann index of the rhyolite is 1.15, less than 3.3. The lithochemistry feature shows that the rhyolite belongs to the calc-alkaline volcanic rocks. Main element features of the andesite show that the SiO₂ content is 55.13%~56.28% and the Na₂O+K₂O content is 4.13%~6.15%. The average Rittmann index of the andesite is 2.20, less than 3.3. The lithochemical features show that the andesite belongs to the calc-alkaline volcanic rocks. The content of the alkaline basalt is 51.49%, Na₂O+K₂O is 6.34%, and the Rittmann index is 4.73, which shows that the basalt belongs to the alkaline volcanic rock. In addition, the granodiorite body of Nyixiong Formation volcanic rocks belongs to aluminous-peraluminous series of enriched LREE. These volcanic rocks are characterized by high LILE (Th, U) and LREE and obvious depletion of HFSE (Nb, Ta). The geochemical compositions of volcanic rocks belong to island arc volcanic rocks.